This invention relates to an articulated bed, and more particularly to an operating mechanism for moving upper and lower body support sections of an articulated bed between raised and lowered positions.
Articulated beds typically include a stationary frame structure to which upper and lower body support sections are pivotably mounted. The lower body support section includes a thigh section and a calf section which are pivotably interconnected with each other at a knee area. The calf section terminates in a foot, which generally remains at a lowered elevation.
In the past, it has been known to provide a separate actuator arrangement for each of the upper and lower body support sections of an articulated bed. Each actuator arrangement typically includes an extendible and retractable actuator member which is movable between extended and retracted positions in response to operation of a drive arrangement such as a motor or a operated crank-type mechanism. With an arrangement of this type, the user can independently adjust the upper body support section and the lower body support section to varying positions as desired. While this system is satisfactory and provides significant flexibility in positioning of the bed sections, it is disadvantageous in that significant costs of materials and installation result from use of two separate actuator members and drive arrangements. This is especially so in the case of separate drive motors, which are heavy and expensive.
It is an object of the present invention to reduce the component and manufacturing costs of an articulated bed by eliminating one of the two drive arrangements and actuator members associated with prior art articulated bed constructions in which separate drive arrangements and actuator members are provided for each of the upper and lower body support sections of the bed. It is a further object of the invention to provide an articulated bed operating mechanism which utilizes a single drive arrangement and actuator member, yet which provides flexibility in the degree of movement of the lower body support section in response to movement of the upper body support section. It is a further object of the invention to provide such an articulated bed operating mechanism which is relatively simple in its components, construction and installation, yet which provides highly satisfactory movement of the upper and lower body support sections between raised and lowered positions. Yet another object of the invention is to provide such an articulated bed operating mechanism which is easy to operate and which requires simple manipulation of components in order to adjust the degree of movement of the lower body support section relative to the upper body support section.
In accordance with the invention, an articulated bed assembly includes a stationary frame structure to which an upper body support section and a lower body support section are pivotably mounted for movement between raised and lowered positions. An actuator arrangement is mounted to the stationary frame structure, and includes an actuator member which is adapted for extension and retraction in response to operation of a drive arrangement, such as a motor. A drive member is interconnected between the actuator member and the upper body support section, for moving the upper body support section between its raised and lowered positions in response to extension and retraction of the actuator member.
An operating mechanism is interconnected between the actuator member and the lower body support section for moving the lower body support section between its raised and lowered positions in response to extension and retraction of the actuator member. In this manner, the upper and lower body support sections are adapted for synchronous movement upon extension and retraction of the actuator member. In a preferred form, the operating mechanism is in the form of a linkage which includes a first link member pivotably mounted to the stationary frame structure and a second link member pivotably mounted to the actuator member. The first and second link members are pivotably connected to each other, to form a scissors-type linkage mechanism. A drive link member is interconnected with the lower body support section and with one of the first and second link members, such that scissors-type movement of the first and second link members in response to extension or retraction of the actuator member results in movement of the lower body support section.
A variable position connection arrangement is associated with the linkage mechanism for providing adjustability in the amount or degree of movement of the lower body support section relative to the upper body support section. The variable position connection arrangement preferably includes a slot formed in the second link member and an engagement pin engageable with the actuator member and receivable within the slot. The slot defines an outer engagement end, and extension of the actuator member results in engagement of the engagement pin with the outer engagement end of the slot for moving the second link member in response to extension of the actuator member. The actuator member includes a series of axially spaced openings along its length, and the engagement pin is adapted to be received within a selected one of the openings so as to vary the amount of extension of the actuator member which is required in order to engage the engagement pin with the outer engagement end of the slot. In this manner, the user is able to vary the degree of movement of the lower body support section relative to the upper body support section simply by moving the engagement pin from one of the openings in the actuator member to another.
In addition, the drive arrangement for the lower body support section can be disabled by removing the engagement pin from the actuator member and the second link member. This releases engagement between the scissors-type linkage mechanism and the actuator member, such that extension and retraction of the actuator member does not result in raising or lowering of the lower body support section. In a preferred form, the pin carries a hanger member, and the pin is received within the slot in the second link member when disengaged from the actuator member. The hanger member is arranged so as to ride on an upper surface defined by the actuator member during movement of the actuator member relative to the second link member. The hanger member accommodates relative movement between the second link member and the actuator member, and also maintains the linkage arrangement in position relative to the actuator member when the linkage mechanism is disabled by removal of the engagement pin.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.